Dynamic Response of Pipes Transporting Fluids

The natural frequency-mass transport velocity relationship was experimentally determined on aluminum tubes throughout a broad mass transport velocity range. Simply-supported, clamped-clamped, and clamped-free conditions were examined. The results are compared with available theoretical developments in each case. Results indicate the theories examined have a range of application limited to the lower transport velocities and even there their application requires knowledge of the no transport reference frequency and the transport dependent axial tension. Process modelling in the higher transport regime is unsatisfactory, and use of the examined theoretical results there should be carefully considered. Since most conditions of instability are associated with high flow velocity, the application of the examined theories to the prediction of response near instability should be done with the clear understanding that large error is possible.